Systems and methods for location of mobile stations (mobile devices) using sensors that perform measurements on uplink signals are known, e.g., as described at U.S. Pat. No. 5,317,323, “Passive High Accuracy Geolocation,” to Kennedy et al. Such sensors connect to existing base station antenna systems, repeater or distributed antenna systems, or antenna systems dedicated to the sensors, e.g., as described at U.S. Pat. No. 7,546,084, “System and method of operation for network overlay geolocation system with repeaters,” to Kennedy et al.
FIG. 1 is a block diagram of a traditional base station architecture. In general, base stations are composed of three main subsystems: an antenna system 101 for receiving/transmitting radio frequency (RF) signals; one or more radio transceivers 102 for conversion to/from baseband signals; and one or more baseband processors 103 for message processing. A typical traditional base station is configured with the antenna system positioned high on a structure 104 such as a tower, building, mountain, etc. The radio transceiver and baseband equipment are housed in an easily accessible cabinet 105, which may be positioned on the ground. The RF signals from the antenna are fed down the structure using a coaxial cable 106. The RF signals typically remain at the RF frequency all the way down the structure. In this architecture a Location Measurement Unit (LMU) sensor 107, installed to perform measurements to support mobile location, can be connected to the RF signals in the equipment cabinet 105 prior to the radio transceiver. This architecture facilitates full access to the mobile uplink signals prior to any signal conversion and processing by the base station.